This invention relates to a surgical instrument or device for dissecting a relatively large organic object into smaller pieces for facilitating removal from the patient. The invention also relates to an associated surgical technique. The instrument and the technique find particular application in laparoscopic surgery.
Laparoscopy involves the piercing of a patient's abdominal wall and the insertion of a cannula through the perforation. Generally, the cannula is a trocar sleeve which surrounds a trocar during an abdomen piercing operation. Upon the formation of the abdominal perforation, the trocar is withdrawn while the sleeve remains traversing the abdominal wall. A laparoscopic instrument, such as a laparoscope or a forceps, is inserted through the cannula so that a distal end of the instrument projects into the abdominal cavity.
Generally, in a laparoscopic surgical procedure, three or four perforations are formed in the abdomen to enable deployment of a sufficient number of laparoscopic instruments to perform the particular surgery being undertaken. Each perforation is formed by a trocar which is surrounded by a sleeve, the sleeves or cannulas all remaining in the abdominal wall during the surgical procedure.
Prior to insertion of the first trocar and its sleeve, a hollow needle is inserted through the abdominal wall to enable pressurization of the abdominal cavity with carbon dioxide. This insufflation procedure distends the abdominal wall, thereby producing a safety space above the patient's abdominal organs. In another, more recently introduced laparoscopic technique, the abdominal wall is lifted mechanically, without insufflation.
Laparoscopic surgery provides several advantages over conventional incision-based surgery. The laparoscopic perforations, in being substantially smaller than the incisions made during conventional operations, are less traumatic to the patient and provide for an accelerated recovery and convalescence. Hospital stays are minimized. Concomitantly, laparoscopic surgery is less time consuming and less expensive than conventional surgery for correcting the same problems.
Laparoscopic surgery is frequently performed to remove a malfunctioning organ such as a gall bladder filled with stones. Generally, a severed bladder is removed from the patient's abdomen by drawing the organ against the distal end of the trocar sleeve and then withdrawing the trocar sleeve with the bladder entrained thereto.
Other organic bodies of substantial size, such as severed myomas, require removal from the abdominal or peritoneal cavity during laparoscopic operations. A myoma is a fibroid mass of tumorous uterine tissue, solid and benign. A myoma can be as large as a baby's head and can squeeze the Fallopian tubes or the uterine cavity, preventing pregnancy. Because a myoma is massive and incompressible, it poses substantial problems in removal from the abdominal cavity via conventional laparoscopic procedures. Unlike a gall bladder, for example, a myoma frequently cannot be simply pulled through a laparoscopic trocar perforation. Moreover, chopping a myoma into smaller tissue parts can cause a significant amount of bleeding.